Was Southwest prohibited from starting an operation at DFW, or are they just stubborn?
Nope, not prohibited initially. Just wanted to use Love, as we were a small, point-to-point intrastate Texas carrier when we started, and using DFW wouldn't have worked for us. Now, we would have to give up a gate at Love field for each and any gate at DFW we used, due to the 2006 compromise agreement between us, American Airlines, and the cities.
Regardless, we still don't want to use DFW; it would hurt our operation. DFW is a huge "fortress" hub, for American's hub-and-spoke operation. During an American wave of departures, you can expect to be on the ground a 45 minutes or more between push and takeoff. With our continual-use operation at Love field (no "banks" of departures), you can push from a gate there, and generally be airborne within minutes. It's worlds more efficient for our type of operation.
Bubba